If your Toppy is as old as your forum joining date, it is certainly in need of some TLC. See Toppy Repairs and PM Andyfras in Fleet for details. Meanwhile I recommend unplugging it from the mains before any further, and possibly more expensive things go wrong. Also it may be possible to recover missing/corrupt files.

Connect the disk to a PC running TopfHDRW and run Scan & Match. It'll take a few hours and it'll recover deleted, as well as wanted, recordings. They'll all need renaming afterwards (another long process).

It's best to do a dsik format before doing this, so that the recovered files are written to a disk with a good file structure.

There is a possibility that the disk is failing; the FAT may be on a bad sector which is why all recordings seem to have disappeared.

If you select 'Write Recovered', you can then put the disk back in the Toppy and step through them. Any that show no duration can be deleted, the others will show the programme title and recording date by pressing the 'i' button. This can be used to rename them to something sensible and unique using Antares/Atair. This can be very time-consuming though.

If all else fails, reformat the disk, reload MyStuff etc., then check the disk using HDDInfo to see if it us showing any errors.

The other cause of disk wipes is poor signal quality. There isn't really a cure, other than improving the signal to the Toppy, and deleting channels on muxes with poor signal.

You can use the Signal Monitor TAP to see what sort of signal quality you're getting (NB: It's the Quality that's important - it needs to be 98% or above; Strength is relatively unimportant, and is often a lot lower.)

If you have installed or updated MyStuff relatively recently - which presumably you have, or will do soon, on your newly formatted drive - you should find the Signal Monitor TAP in the Utilities folder.

NB: If you haven't already found it, Geoff Bacon's TopManager for Windows is a good utility that allows you to backup your /ProgramFiles directory (and therefore all your TAPs and their settings) to your PC in just a couple of minutes.

If you can still obtain deallocation errors, I suggest you try to identify the culprit as follows: In TM
1) Connection| Browse
2) Double click Auto Start
3) Select a tap file, Right Click and Rename. Add .xxx to the filename e.g. MyStuff.tap to MyStuff.tap.xxx
4) Reboot toppy (ignore any deallocation error)
5) Do some toppy operations and/or wait 5 mins (in case it is EPG2MEI)
6) Shut toppy down and see if you still get deallocation errors (if you do, try disabling another tap and repeat the 3 to 6 above)
7) When you want to put the toppy back as it was, just rename the files back to .tap by removing the .xxx

Note: I am renaming the files rather than moving them out of Auto Start because this preserves their original load position when the files are renamed.

[edit]Although the above may identify a tap, it may not be the culprit - it may just be interacting with another tap[/edit]
Geoff